memset-1.c

linux下编程用 编译软件

/* Copyright (C) 2002, 2005  Free Software Foundation.

   Test -minline-all-stringops memset with various combinations of pointer
   alignments and lengths to make sure builtin optimizations are correct.
   PR target/6456.

   Written by Michael Meissner, March 9, 2002.
   Target by Roger Sayle, April 25, 2002.  */

/* { dg-do run { target i?86-*-* x86_64-*-* } } */
/* { dg-options "-O2 -minline-all-stringops" } */

extern void *memset (void *, int, __SIZE_TYPE__);
extern void abort (void);
extern void exit (int);

#ifndef MAX_OFFSET
#define MAX_OFFSET (sizeof (long long))
#endif

#ifndef MAX_COPY
#define MAX_COPY (8 * sizeof (long long))
#endif

#ifndef MAX_EXTRA
#define MAX_EXTRA (sizeof (long long))
#endif

#define MAX_LENGTH (MAX_OFFSET + MAX_COPY + MAX_EXTRA)

static union {
  char buf[MAX_LENGTH];
  long long align_int;
  long double align_fp;
} u;

char A = 'A';

main ()
{
  int off, len, i;
  char *p, *q;

  for (off = 0; off < MAX_OFFSET; off++)
    for (len = 1; len < MAX_COPY; len++)
      {
	for (i = 0; i < MAX_LENGTH; i++)
	  u.buf[i] = 'a';

	p = memset (u.buf + off, '\0', len);
	if (p != u.buf + off)
	  abort ();

	q = u.buf;
	for (i = 0; i < off; i++, q++)
	  if (*q != 'a')
	    abort ();

	for (i = 0; i < len; i++, q++)
	  if (*q != '\0')
	    abort ();

	for (i = 0; i < MAX_EXTRA; i++, q++)
	  if (*q != 'a')
	    abort ();

	p = memset (u.buf + off, A, len);
	if (p != u.buf + off)
	  abort ();

	q = u.buf;
	for (i = 0; i < off; i++, q++)
	  if (*q != 'a')
	    abort ();

	for (i = 0; i < len; i++, q++)
	  if (*q != 'A')
	    abort ();

	for (i = 0; i < MAX_EXTRA; i++, q++)
	  if (*q != 'a')
	    abort ();

	p = memset (u.buf + off, 'B', len);
	if (p != u.buf + off)
	  abort ();

	q = u.buf;
	for (i = 0; i < off; i++, q++)
	  if (*q != 'a')
	    abort ();

	for (i = 0; i < len; i++, q++)
	  if (*q != 'B')
	    abort ();

	for (i = 0; i < MAX_EXTRA; i++, q++)
	  if (*q != 'a')
	    abort ();
      }

  exit(0);
}